Sniffing like a fly

Dorsal view of a cutaway fly head showing the main elements of the olfactory pathway. Credit: Nature Reviews Neuroscience

Researchers from UK and Australia have decided to take hints from a fly, the drosophila melanogaster (fruit fly), to develop an artificial nose.

The fruit fly olfactory receptors are extremely sensitive to a variety of "smells" and interestingly they are also good at detecting odours that are not part of the fly normal experience. In their research they have discovered that the receptors can distinguish among 36 chemicals related to wine (the wine set) and 35 related to hazardous substance (industrial set). The fly can manage this by using 20 different types of receptors. Its ability to discern among the "wine set" odours is not surprising since the fly diet is based on grape and fermented fruits, what was surprising is their ability to discriminate among the "industry set".

Today's "artificial noses" are based on the reaction of metal oxides to odorous molecules but they are slow compared to insects receptors, one thousand times slower! Insects have a wide range of receptors, some species have 300 of them. The fruit fly has only 20 and this is what makes them so interesting: the less they are the cheaper to build them in an artificial nose. In addition the researchers have determined that by using just 10 different types of the fly receptors they can get enough data to distinguish odours with a 90%t precision. These measurements were made by detecting spikes on the neurones activated by the receptors.

The next step is to mimic the fly receptors identified into an artificial nose. Not to sniff wine - I guess they will take care of that personally ;-) but to detect hazardous materials like explosives.

Amazing what Nature can teach us if we take the time to learn from it.